The present invention relates generally to a material feed system for a cutting machine, and relates specifically to the simultaneous movement of a vise carriage and moveable support rollers for moving, positioning, and supporting material on a roller table.
It is well known to use a roller table having a vise carriage, also referred to as a shuttle vise, for movement of material to and from a cutting machine. For effectuating movement of the vise carriage, it is known in the art to use belts and pulleys, drive screws and drive sleeves, hydraulic cylinders and piston rods, or racks and pinions, as described in U.S. Pat. Nos. 4,241,630 and 6,698,159. Specifically, U.S. Pat. No. 4,241,630 teaches how to move a vise carriage by mounting a hydraulic cylinder to the frame of the roller table and attaching the distal end of the piston rod to the vise carriage. It is also known in the art to use a rack-and-pinion system to control movement of the vise carriage wherein the rack is fixed to the vise carriage and the pinion is fixed to the frame of the table. With such a configuration the movement of the vise carriage can be controlled via a servomotor or a manual crank attached to the pinion.
There are some drawbacks with the currently known means of effectuating movement of a vise carriage. For example, when a hydraulic cylinder and piston rod are used, the vise carriage's range of movement is limited to the stroke of the hydraulic cylinder, effectively limiting the range of movement of the vise carriage to less than half the length of the table.
It is also well known to use a series of rollers for supporting and allowing free movement of material on a roller table. Generally, a series of fixed rollers are provided and are located equally spaced along the length of the table. Such a configuration would require the vise carriage to have an overhead support tying both sides of the vise together in order to allow the vise carriage to freely pass over the rollers. An overhead support, however, is problematic because it prevents the loading of material from above the vise.
To obviate the need for an overhead support, a first alternative known in the art is to exclude roller supports from within the range of movement of the vise carriage and include roller supports fixedly attached to the vise carriage. An example of such a design is the Armstrong-Blum Marvel Series 81 APC Sawing System. However, those in the industry have experienced problems with shorter pieces of material falling into the open area between the roller supports which are attached to the vise carriage and the adjacent roller supports which are attached to the frame of the table.
To minimize the unsupported span of material, it is known in the art to include a movable roller support which is situated adjacent to the movable vise carriage. The movable roller support is attached to the vise carriage in such a manner that, when the vise carriage is moved away from the roller support, the roller support remains stationary until it is a predetermined distance from the vise carriage, at which point the roller support moves with the vise carriage. Likewise, when the vise carriage is moved towards the roller support, the roller support remains stationary until the vise carriage abuts the roller support, at which point the roller support moves with the vise carriage. This means of support is also not preferable because the operation of the roller support is not smooth; the roller support is impacted or jerked by the vise carriage when it begins to move.
Thus, there is a need for increasing the stroke of a vise carriage when used in combination with a hydraulic cylinder and piston rod. Also, there is a need for improved support for a piece of material being moved by a vise carriage. It is therefore a primary object of the invention described and claimed herein to provide a mechanism to multiply the stroke of a hydraulic cylinder and piston rod to provide a wide range of movement for a movable vise carriage. It is a further object of the inventions described and claimed herein to provide a movable support which moves smoothly in concert with the vise carriage for minimizing the unsupported length of material being moved by the vise carriage. It is another object of the inventions describe and claimed herein to provide means for material support for a roller table having a vise carriage without an overhead support. It is another object of the inventions described and claimed herein to provide a mechanism to effectuate concurrent movement of the roller support and vise carriage.
The present invention solves the problems inherent in existing designs by providing moveable roller supports which move in chorus with a moveable vise carriage to ensure that the length between adjacent material support points are minimized. In the preferred embodiment of the present invention, there are two moveable roller supports. The first movable roller support is located approximately at the midpoint of the span between the moveable vise carriage and a stationary vise. The second movable roller support is located on the opposite side of the movable vise carriage and is integral with the first movable roller support. Throughout the entire stroke of the moveable vise carriage, the moveable roller supports move concurrently such that the first support is always located at approximately the midpoint of the span. In an alternative embodiment, the moveable roller supports are located at predetermined locations and move at approximately half the velocity of the moveable vise carriage. In yet another embodiment, the moveable roller supports are located at predetermined locations and, for a given distance traveled by the moveable vise carriage, the moveable roller supports move approximately half that distance. Alternatively, the moveable roller supports can move at some other predetermined ratio of the velocity or the traveled distance of the movable vise carriage. In yet another alternative embodiment, there can be any number of movable roller supports which integrally or independently move.
The preferred means for controlling the movement of the roller supports and the vise carriage is a mechanism comprised of a hydraulic cylinder and piston rod used in combination with a rack-and-pinion system to provide a doubling effect on the stroke of the hydraulic cylinder. The hydraulic cylinder is fixed to the frame of the table and the piston rod movably extends from the hydraulic cylinder. The rack-and-pinion system has a pinion attached to the distal end of the piston rod and has two racks, one of which is fixed to the frame of the machine while the other is attached to the movable vise carriage. The two racks are located opposite each other along a diameter of the pinion and are parallel to the length of the machine (parallel to the direction of material movement). In a typical rack and pinion system, the pinion is stationary and is powered either by a hand crank or a servomotor. However, in the present invention, the pinion moves laterally (because it is attached to the distal end of the piston rod), while simultaneously engaging with the rack which is fixed to the frame and engaging with the rack which is attached to the movable vise carriage. This configuration effectively causes the movable vise carriage to move twice the distance and velocity of the piston rod. This configuration allows for a doubling of the stroke of the hydraulic cylinder and piston rod; i.e., the range of movement of the movable vise carriage is twice the stroke of the piston rod. The movable support is fixed to the pinion and the piston rod and, thus, will move half at half the velocity and distance as the movable vise carriage.
One skilled in the art will understand that the movement of the movable vise carriage and movable roller support can be controlled electronically. This would likely entail using a computer in combination with potentially separate means for effectuating movement of the of the vise carriage and roller supports. The mean for effectuating movement could include servomotors, hydraulic cylinders and piston rods, rack-and-pinions, pulley systems, and/or drive screws and drive sleeves.
It should be understood that the drawings are not necessarily to scale and that the embodiments are sometimes illustrated by graphic symbols, phantom lines, diagrammatic representations and fragmentary views. In certain instances, details which are not necessary for an understanding of the inventions described and claimed herein or which render other details difficult to perceive may have been omitted. It should be understood, of course, that the inventions described herein are not necessarily limited to the particular embodiments illustrated herein.
Like reference numerals will be used to refer to like or similar parts from Figure to Figure in the following description of the drawings.